1. Field of the Invention
This invention relates to a method of feeding an ink ribbon in a printer, and more particularly to an improvement of a method of feeding an ink ribbon in a printer for the purpose of increasing the durability of the ink ribbon which is reversed at the ribbon ends.
2. Description of the Prior Art
In various kinds of printers, especially in impact type printers, printing on the recording paper is performed by striking an ink ribbon which is horizontally arranged along the recording paper, since high printing quality can be easily attained with such a simple structure and at a low price.
As has been well-known, this ink ribbon is driven and fed continually in accordance with the imprinting action and wound on one of the reels provided on both sides of the recording paper or a printing head. Normally, the ink ribbon spanned between the pair of reels is reversed in its feeding direction and continues its frequent use in the imprinting action. Accordingly, the ink ribbon can be effectively used many times.
However, in such a feeding method in the prior art, partial damage to the ink ribbon easily occurs under actual printing conditions. Especially, extreme damage to the small sections in the vicinity of the ribbon ends cause a total abandonment of the ink ribbon despite the fact that the other major portion is sufficiently fit for use. Such problem mentioned above has been more evident in the printer in which the printing speed has been extremely increased in the recent years, and the improvement for prevention of the above drawbacks has been strongly required.
In FIG. 1 shown therein is a damaged state of the ribbon according to the conventional feeding method described above. The ink ribbon 14 spanned between the pair of reels 10 and 12 is used at the hatched portion in the center of the ribbon 14, and is reversed in its motion at its both ends X and Y, as has been well-known, so that the center area can be brought in use for the printing action again.
If such reversing motion of the ribbon 14 were instantly and ideally performed, the ink ribbon 14 could be used with extreme uniformity. However, it is impossible in substance to perform the instant reverse motion of the ribbon 14, and it is inevitable in the recent printers with a high speed ribbon feeding system that the ink ribbon 14 does not follow the rotation of a feeding motor and becomes loose at its ends in the reverse motion.
In the conventional method of feeding the ink ribbon it makes temporary stops or loose in its reverse motion, as is mentioned above, but continuous imprinting action is performed during its reversing motion since the imprinting action on the printer has been paid no attention to. In FIG. 1 shown therein is such a case that the repeating use of the same place for the frequent imprints in the vicinity of the ribbon ends X and Y cause excessive use of the ink ribbon 14, which accelerates damages so rapidly that unfavorable ribbon tear accidentally occurs in the extreme case. Such excessive use in the particular sections also causes such serious imprint failure that this ink ribbon must be abandoned despite the fact that the center area can be still sufficiently fit for use and the maintenance cost will be greatly increased.